content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2012, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
   * Other names may be trademarks of their respective owners.]
   *
   * -------------------
   * DialBackground.java
   * -------------------
   * (C) Copyright 2006-2012, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 03-Nov-2006 : Version 1 (DG);
   * 16-Oct-2007 : The equals() method needs to call super.equals() (DG);
   * 15-Jun-2012 : Removed JCommon dependencies (DG);
   *
   */
  
  package org.jfree.chart.plot.dial;
  
  import java.awt.Color;
  import java.awt.GradientPaint;
  import java.awt.Graphics2D;
  import java.awt.Paint;
  import java.awt.geom.Rectangle2D;
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.io.Serializable;
  
  import org.jfree.chart.HashUtilities;
  import org.jfree.chart.ui.GradientPaintTransformer;
  import org.jfree.chart.ui.StandardGradientPaintTransformer;
  import org.jfree.chart.util.PaintUtilities;
  import org.jfree.chart.util.PublicCloneable;
  import org.jfree.chart.util.SerialUtilities;
  
  /**
   * A regular dial layer that can be used to draw the background for a dial.
   *
   * @since 1.0.7
   */
  public class DialBackground extends AbstractDialLayer implements DialLayer,
          Cloneable, PublicCloneable, Serializable {
  
      /** For serialization. */
      static final long serialVersionUID = -9019069533317612375L;
  
      /**
       * The background paint.  This field is transient because serialization
       * requires special handling.
       */
      private transient Paint paint;
  
      /**
       * The transformer used when the background paint is an instance of
       * <code>GradientPaint</code>.
       */
      private GradientPaintTransformer gradientPaintTransformer;
  
      /**
       * Creates a new instance of <code>DialBackground</code>.  The
       * default background paint is <code>Color.WHITE</code>.
       */
      public DialBackground() {
          this(Color.WHITE);
      }
  
      /**
       * Creates a new instance of <code>DialBackground</code>.  The
       *
       * @param paint  the paint (<code>null</code> not permitted).
       *
       * @throws IllegalArgumentException if <code>paint</code> is
       *     <code>null</code>.
       */
      public DialBackground(Paint paint) {
          if (paint == null) {
              throw new IllegalArgumentException("Null 'paint' argument.");
          }
          this.paint = paint;
          this.gradientPaintTransformer = new StandardGradientPaintTransformer();
      }
  
      /**
       * Returns the paint used to fill the background.
       *
       * @return The paint (never <code>null</code>).
       *
       * @see #setPaint(Paint)
       */
      public Paint getPaint() {
          return this.paint;
      }
  
      /**
       * Sets the paint for the dial background and sends a
       * {@link DialLayerChangeEvent} to all registered listeners.
       *
       * @param paint  the paint (<code>null</code> not permitted).
       *
       * @see #getPaint()
       */
      public void setPaint(Paint paint) {
          if (paint == null) {
              throw new IllegalArgumentException("Null 'paint' argument.");
          }
          this.paint = paint;
          notifyListeners(new DialLayerChangeEvent(this));
      }
  
      /**
       * Returns the transformer used to adjust the coordinates of any
       * <code>GradientPaint</code> instance used for the background paint.
       *
       * @return The transformer (never <code>null</code>).
       *
       * @see #setGradientPaintTransformer(GradientPaintTransformer)
       */
      public GradientPaintTransformer getGradientPaintTransformer() {
          return this.gradientPaintTransformer;
      }
  
      /**
       * Sets the transformer used to adjust the coordinates of any
       * <code>GradientPaint</code> instance used for the background paint, and
       * sends a {@link DialLayerChangeEvent} to all registered listeners.
       *
       * @param t  the transformer (<code>null</code> not permitted).
       *
       * @see #getGradientPaintTransformer()
       */
      public void setGradientPaintTransformer(GradientPaintTransformer t) {
          if (t == null) {
              throw new IllegalArgumentException("Null 't' argument.");
          }
          this.gradientPaintTransformer = t;
          notifyListeners(new DialLayerChangeEvent(this));
      }
  
      /**
       * Returns <code>true</code> to indicate that this layer should be
       * clipped within the dial window.
       *
       * @return <code>true</code>.
       */
      @Override
      public boolean isClippedToWindow() {
          return true;
      }
  
      /**
       * Draws the background to the specified graphics device.  If the dial
       * frame specifies a window, the clipping region will already have been
       * set to this window before this method is called.
       *
       * @param g2  the graphics device (<code>null</code> not permitted).
       * @param plot  the plot (ignored here).
       * @param frame  the dial frame (ignored here).
       * @param view  the view rectangle (<code>null</code> not permitted).
       */
      @Override
      public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame,
              Rectangle2D view) {
  
          Paint p = this.paint;
          if (p instanceof GradientPaint) {
              p = this.gradientPaintTransformer.transform((GradientPaint) p,
                      view);
          }
          g2.setPaint(p);
          g2.fill(view);
      }
  
      /**
       * Tests this instance for equality with an arbitrary object.
       *
       * @param obj  the object (<code>null</code> permitted).
       *
       * @return A boolean.
       */
      @Override
      public boolean equals(Object obj) {
          if (obj == this) {
              return true;
          }
          if (!(obj instanceof DialBackground)) {
              return false;
          }
          DialBackground that = (DialBackground) obj;
          if (!PaintUtilities.equal(this.paint, that.paint)) {
              return false;
          }
          if (!this.gradientPaintTransformer.equals(
                  that.gradientPaintTransformer)) {
              return false;
          }
          return super.equals(obj);
      }
  
      /**
       * Returns a hash code for this instance.
       *
       * @return The hash code.
       */
      @Override
      public int hashCode() {
          int result = 193;
          result = 37 * result + HashUtilities.hashCodeForPaint(this.paint);
          result = 37 * result + this.gradientPaintTransformer.hashCode();
          return result;
      }
  
      /**
       * Returns a clone of this instance.
       *
       * @return The clone.
       *
       * @throws CloneNotSupportedException if some attribute of this instance
       *     cannot be cloned.
       */
      @Override
      public Object clone() throws CloneNotSupportedException {
          return super.clone();
      }
  
      /**
       * Provides serialization support.
       *
       * @param stream  the output stream.
       *
       * @throws IOException  if there is an I/O error.
       */
      private void writeObject(ObjectOutputStream stream) throws IOException {
          stream.defaultWriteObject();
          SerialUtilities.writePaint(this.paint, stream);
      }
  
      /**
       * Provides serialization support.
       *
       * @param stream  the input stream.
       *
       * @throws IOException  if there is an I/O error.
       * @throws ClassNotFoundException  if there is a classpath problem.
       */
      private void readObject(ObjectInputStream stream)
              throws IOException, ClassNotFoundException {
          stream.defaultReadObject();
          this.paint = SerialUtilities.readPaint(stream);
      }
  
  }
  